ALUMINA CATALYST: SYNTHESIS OF NOVEL QUINAZOLINE DERIVATIVES AND THEIR SOLUBILITY INCREASES THROUGH INCLUSION WITH Β-Cyclodextrin

Abstract

Objective: To synthesis a novel methodology of bioactive quinazoline derivatives under greener process to an excellent yields and increases their solubility via inclusion with β-cyclodextrin (CD).
 Methods: Derivatives of quinazoline compounds were prepared by the mixture of 3-amino-2-phenylquinazolin-4(3H)-one, derived from 2-phenyl-4H-benzo[1,3]oxazin-4-one by refluxing with hydrazine, substituted aromatic aldehyde and alumina intimately in an agate mortar and pestle under solvent-free condition. Using various techniques for preparing inclusion complexes, kneaded method is the best method for encapsulation in host-guest complex chemistry. All compounds including inclusion complexes were characterised by spectral methods.
 Results: Synthesized a series of novel quinazoline compounds under a very easier greener process with a commercially available reagent. However, their low bioavailability, due to low absorption and solubility, can limit their potential applications. CD was used to resolve this solubility problem. CD can easily accommodated the guest molecules to encapsulate inside its cavity due to interior the hydrophobic nature with a hydrophilic exterior part to form thermodynamically more stable molecular microcapsules, commonly name as host-guest complexes or inclusion complexes. In this sense, CD was utilized to enhance not only the solubility and bioavailability of these quinazoline compounds but also their antibacterial capacity. The formation of inclusion complex was thus confirmed by ultraviolet-visible spectroscopy (UV-VIS), Fourier Transform Infrared Spectrometry (FT-IR), differential scanning calorimetry (DSC) and solubility study technique.
 Conclusion: Here we have successfully unfolded an eco-friendly methodology for the synthesis of derivatives of quinazoline and increased their solubility via host-guest inclusion technique. From the spectral analysis, it was concluded that the quinazoline compound is fully encapsulated inside the cavity of the CD.

A Review on Benzimidazole Heterocyclic Compounds: Synthesis and Their Medicinal Activity Applications

“…The available methodologies for organic synthesis of heterocyclic compounds have been steadily improving with respect to not only the economic field, but also the environmental aspect, which is very important for future sustainability considerations. 16 Heterocyclic compounds are organic compounds consisting of a single ring or a polycycle and they contain at least one heterocyclic atom such as oxygen, nitrogen, sulfur and others. 17 In this review, we focus on benzimidazoles, and discuss their properties, methods of synthesis, as well as their important biological applications.…”